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  • When we send a mission to Mars to search for ancient life, where should it land? A crater

  • filled with glassyes, GLASSmight be a good place to start.

  • Hello, I’m Ian O’Neill, space producer for Discovery News and today I wanted to take

  • a quick trip onto the tantalizing surface of Mars.

  • As depicted in the AWESOME-looking trailer for the new Matt Damon movieThe Martian,”

  • the Red planet looks like a barren and poisonous place. To survive, Damon’s character, astronaut

  • MARK WATNEY, mustscience the shitout of his temporary habitat to survive after

  • being left for dead by his crew.

  • But as our armada of space robots are showing us, Mars hasn’t always been the dry and

  • deadly environment it is now -- Mars was once a wet world containing the ingredients for

  • life and it looks like meteorite craters may be the best place to look for any ancient

  • lifeforms that could have evolved millions of years ago.

  • We all know that the Red Planet is littered with craters and interesting geological features,

  • and it just so happens that NASA’s getting very familiar with the minerals that cover

  • the Martian surface.

  • In new research, one particular instrument on board NASA’s Mars Reconnaissance Orbiter

  • called CRISM has been used to look deep into a few impact craters to look for glass.

  • But why glass?

  • Well, in 2014, researchers headed by Brown University found glass deposits at the bottom

  • of an Argentinian meteorite impact crater that was formed millions of years ago. Entombed

  • inside this glass was organic material that was existing at the site when the meteorite

  • hit Earth.

  • Glass can form when minerals in rock are exposed to sudden heating -- so the extreme impact

  • pressures and searing heat generated during a meteorite impact can produce certain types

  • of glasses.

  • Like those Jurassic era mosquitos entombed inside amber, any ancient organic matter can

  • befrozen in timewithin this glass, providing us with a cool look into a biological

  • time capsule dating back millions of years.

  • So, by turning their gaze to Mars, researchers pondered whether Mars also has glass in its

  • craters, potentially also containing biosignatures of hypothetical ancient Mars life.

  • But the chemical signature of glass on Mars is very hard to detect.

  • In an effort to confront this, the Brown team put similar powdered minerals found on Mars

  • into an oven and heated it to form glass in the lab. They then studied light reflected

  • off the lab glass to measure its spectroscopic fingerprint.

  • Then, using CRISM, the researchers sought out regions on Mars that generated a similar

  • fingerprint when compared with the lab sample. And then they saw it, craters on Mars containing

  • glassy material!

  • The most exciting thing is that one of the craters found to contain glass is HARGRAVES

  • CRATER near NILI FOSSAE, a 400-mile-long trough in the Martian surface. And it just so happens

  • that this is one of the landing site options for NASA’s Mars 2020 sample return mission.

  • Should the rover find glass in that area, and might we be able to analyse the stuff

  • the samples contain, could the glass have the fossilized remains of ancient Mars microbes

  • inside? Who knows, but it would be cool to find out.

  • Do you think we should send a manned expedition to search for Mars fossils? Let us know what

  • you think in the comments below, and if youre interested in how were currently looking

  • for Mars life, check out Amy’s recent video.

When we send a mission to Mars to search for ancient life, where should it land? A crater

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古代火星生命被凍在玻璃裡嗎? (Is Ancient Mars Life Frozen In Glass?)

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    羅紹桀 發佈於 2021 年 01 月 14 日
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